The good Samaritan was in town for just one day to visit her parents and decided to take a jog around the reservoir before meeting with her parents for dinner.

Rebecca said she doesn't want her last name to be used, but said she was jogging around the Brookline Reservoir when she said she spotted trouble.

"On my second lap, about 100 years away, I noticed that the women had their backs turned and the stroller was moving toward the reservoir," she said.

The double stroller rolled over the steep embankment, a 10-foot drop, with two children face down in the water.

"I jumped in and flipped the carriage and the children were buckled in," she said. "At that point I was waterlogged and I couldn't really take it out."

The water was too deep to stand in, but luckily the Brookline High School graduate is also a former lifeguard.

"The babies were down, so I was kind of thinking in my head, 'I hope I hear them cry. I hope I hear them cry,'" she said. "So as soon as I flipped it one of the little girls started crying. So I was like, 'OK. They were not in there for too long.'"

A boy and a girl, 1 1/2 and 4 years old, their mother frantically tried to help and the situation almost got worse.

"One of the women jumped in, but she couldn't swim," Rebecca said. "So she went in trying to help but ended up grabbing me."

Eventually Rebecca was able to drag all three closer to the edge, where others helped to get them out.

Police have but one word to describe what she did.

"It's unbelievable," Sgt. Robert Disario said. "I think God has a plan or there is a higher power that has a plan. She was meant to be here to save those kids."

Rebecca was visiting from Manhattan where she now lives and was in town for her father's birthday.

"I came to Boston for a day and never thought this would happen," she said. "But, yeah, I'm glad I could be there."

Police said it appeared as though the children's mother and her friend were talking and didn't realize the stroller's brakes were not on when it rolled into the reservoir and said it appeared to be an accident.